Lamp socket



Dec. 14, 1937. G. A. JOHNSON LAMP SOCKET Filed Nov. 1'7, 1935;

NEY.

Patented Dec. 14, 1937 UNITED STATES PATENT OFF-ICE GustafA. Johnson, New Bedford, Mass. Application November 1'7, 1933, Serial No. 698,462

12 Claims.

This invention relates to electric lamp sockets and is exemplified in a socket of the push 'button type.

The general object of the invention is the provision of a lamp socket which is of simple and compact form, easily assembled and durable and highly eflicient in its operation. 1

One of the specificobjects of the invention is the provision of a switch structure for a lamp socket which permits the socket to be used with lamps of high watt rating.

Another specific object of the invention is the provision for a lamp socket of an insulating body and switch structure which materially reduces the length of the socket as compared with a standard socket in order to permit its use in fixtures requiring a short socket and-at the same time to effect a saving in material and a reduction in cost of manufacture.

A further object of the invention is the .provision of an insulating body of such form as to facilitate the attachment of lead wires to the fixed contacts carried thereby.

Another object of the invention is the provision of an improvedswitch structure in which the various parts are held in operating position in the insulating body by the actuating spring without requiring any other supporting and fastening means.

Yet another object is the provision for bridging a pair of fixed contacts of a rocker member having resilient arm portions adapted to accommodate themselves to the fixed contacts in order to break the circuit at two points simultaneously.

Other objects of the invention will be inpart obvious and in part described more specifically hereinafter.

In attaining the foregoing objects, my invention in its preferred form contemplates a lamp socket comprising an insulating body carrying a lamp receiving screw shell, fixed contacts and a switch structure for closing and opening a circuit through said contacts, all these parts being enclosed in a socket or casing of any suitable construction. The novel features of my invention reside in the form and construction of the insulating body and the switch parts and in the relative arrangement of the switch parts in the insulating body.

One of the important features of the invention consists in providing an insulating body recessed in both its bottom and top faces, the former serving as a switch chamber and the latter as a space for knotting the lead wires. The recess in thetop face opens out opposite sides of the insulating pact fiat cap may be used in conjunction withithe shell instead of the usual dome-shaped cap.

Another important feature of the invention resides in the method of mounting the rocker member of the switch in the insulating body. The

switch chamber in said body opens intothe recess in the top face through a slot provided with an interior shoulder'at each end adjacent the floor of said recess. The head of the rocker member is provided with ears adapted to engage said shoulders and support said rocker member in rocking position when its head is loosely mounted in said slot. The floor of the recess in the top face of the insulating body is raised in the centerso. that the slot and the pivotal axis of the rocker member are brought nearer the top face'of the insulating body. By means of this construction, the length of the insulating body may be shortened and a more compact structure obtained. The'combina tion ,of this feature with the knotting recess in the top face of the insulating body 'permitting'the use of a fiat cup produces a socket of muchshorter length than the standard socket, which is of especial advantage because it permits the socket to be used in fixtures in which the space available for a lamp socket is inadequate fora standard socket.

Another important feature of the invention consists in so forming'the insulating body'and arranging the switch parts in relation to said body and to each other that the actuating spring of the switch serves to retain all of said parts in their respective positions in said insulating body and in proper relation to each other without requiring contact portions which are normally separated a V greater distance thanthe gap between the pair of fixed contacts tobe bridged by the rocker I member, so that when the resilient contact p'ortions are thrown in between the fixed contacts to close the circuit, they are slightly compressed together. This not only results in an efficient contact between the resilient portions of the rocker member and the fixed contacts but also insures a simultaneous separation of the resilient portions from the fixed contacts when the rocker member is thrown out of bridging position. The circuit is thereby broken at two points simultaneously which splits the current and reduces arcing to a. m imum. Important advantages of this construction are that the efficiency and durability of the switch are greatly increased and such, for instance, as 660 watt lamps.

In the accompanying drawing, my invention is shown embodied in a lamp socket of the push 7 button type in which,

Figure 1 is a view in perspective of a lampsocket constructed and adapted to be operated in accordance with my invention.

Fig. 2 is a vertical central sectional view of same.

Fig. 3 is an exploded view in perspective of the various parts of the lamp socket omitting the switch mechanism.

Fig. 4 is a bottom plan view of the insulating body and the switch mechanism looking upwardly in Fig. 2. I, T

Fig. 5 is a vertical cross sectional view of the insulating body showing the rocker member in elevation.

Fig. 6 is a view in perspective of the insulating disk and central contact carried thereby.

Fig. 'I is a bottom plan view of the insulating body and screw shell looking upwardly in Fig. 2.

Fig. 8 is a vertical sectional view, similar to Fig. 2, of the upper portion of the socket provided with a fiat cap instead of a dome-shaped cap.

Referring to the drawing, l indicates an insulating body made of porcelain or other suitable insulating material which is preferably in the form of a circular block having in its bottom face a rectangular recess ll serving ,as a switch chamber and in its top face a recess I2 for permitting the lead wires to be knotted. The latter recess, I2 is relatively-deep and opens out opposite sides of said insulating body and is continued entirely down one side at I3 and partially down the other side at [4 (Fig. 3) to form side recesses for receiving and holding a pair of terminals. This formation of the top of the insulating body leave-s a pair of oppositely disposed upstanding curved walls and IS, the inner faces of which are inclined so that the walls increase in thickness in a downward direction. I

. The fioor of the recess l2 slopes upwardly from the bases of the curved walls I5 and 16 so that the center of the floor is raised and in this raised center is a slot H which expands downwardly into the switch chamber II (Fig. 2) thereby connecting the recess I2 with that chamber. At each end of the slot adjacent the fioor of the recess l2 there is formed an interior shoulder 18 (Fig- 5) which shoulders are intended to constitutebearings for a switch rocker member.

Fastened to its bottom face, the insulating body carries a lamp receiving screw shell 20 of ordinary and well known construction. The bottom face 2| of the insulating body is slightly recessed to leave a marginal rim 22 (Fig. 4) within which is fitted the base of the screw shell. To insulate the-shell from the switch parts, a disk 24 (Fig. 6)

of sheet insulating material is interposed between the bottom face 2| of the insulating body and the base of the shell and these parts are fastened to said body by a screw 25 and a shell terminal 26 (Fig. 7). The screw 25 passes through holesr2'l and 28 in the base of the shell and insulating disk respectively and is threaded into a hole 29 (Fig. 4) in the bottom of the insulating body.

The shell terminal 26 is mounted in a vertical slot 30 in the insulating body extending downwardly from the side recess l4 and opening out the bottom face of said body in register with slots 3| and 32 in the disk 24 and base of the shell respectively and the bifurcations 33 of the end of the terminal are turned over on a washer 34 on the inner face of the base of the screw shell to fastenit at that point to the insulating body (Fig. 7). For registering the disk 24 in proper position on the bottom face of the insulating body in the assembling process, said face is provided with a round projecting lug 35 adapted to fit a hole 3 6 in the disk (Figs. 3 and 4). To prevent vertical movement of the terminal 26 in the slot 30, it is provided with shoulders 38 (Fig. 3) adapted to engage the sides of the top opening of the slot, and the upper part of the terminal which lies exposed in the side recess l4 carries a binding screw 39 for attaching a lead wire thereto.

In the other side recess I3 is mounted another terminal 40 carrying a binding-screw'fl. This terminal has a portion 42which extends into the switch chamber l l to serve as a fixed contact. Mounted in a slot 43 in the insulating disk 24 is a central contact 44 *(Fig. 6), one end 45 of which is positioned onthe lower face of the disk and extends through an opening 46 in the base of the screw shell 20 for engagement by the central contact on a lamp when mounted therein. The other end 41 of the contact 44 on the upper side of the disk extends into the switch chamber to serve as a fixed contact. s

For closing and opening a lamp circuit between the two fixed contacts 42 and 41 in the switch chamber, a switch structure is provided which may be of any suitable form. Preferably, however, it comprises a rocker member 50, an actuating spring 5| and an operating member 52.

The rocker member 50 is U-shaped and is preferably made of suitable wire bent into the form shown in Figure 5 and wire is preferable for the reason that the arms of the rocker member may be thereby made resilient. If necessary the arms may be tempered to obtain proper resiliency. The rocker member is pivotally mounted in the slot I! in the insulating body with its arms extending into the switch'chamber and its head is provided with end ears 53 journalled on the interior shoulders l8 in the slot to support it in that position. The ends of the two arms of the rocker member are turned inwardly toward each other and then in a reverse direction.

The, actuating spring 5| of helical form has part of the insulating body is: provided with a diametrical slot opening out" opposite sides and the bottom of said body and. into the switch chamber and the slide is mounted therein in em gagement with the ceiling ofsaid slot with the push buttons projecting from the sides of said body accessible, for operation. For connecting the spring 5| to the slide, the latter is provided with a longitudinal slot 51 having a center cross piece 58 and the former has inserted in its upper end a shouldered link 60 having a slotted end for engaging said cross piece 58. Since the actuating spring is under compression at all times, it exerts a downward pressure upon the rocker member which holds its seated in the slot l1 and an upward pressure on the shouldered link to hold the slide. member seated on the ceiling of the diametrical slot 55. The actuating spring thereby serves to hold the switch parts in operative relation to each otherwithout requiring fastening means or supporting means other than the insulating body. To limit the longitudinal movement of the slide 52 in both directions, two studs 62 are formed on the ceiling of the diametrical slot 55 which project into the slot 51 in the slide 52 to serve as stops to limit the movement of the slide in both directions.

It will be observed that the operating slide member is located between the pivotal axis and the ends of the arms of the rocker member and that the pivotal axis is positioned in the floor of the recessed top of the insulating body, all of which produces a switch which is very compact and which may be housed in a very short insulating body.

The rectangular switch chamber H is preferably of a form and size just suificient to house the rocker member and to limit its travel in both directions. The side walls thereof converge slightly in an upward direction toward the slot I I to conform to the shape of the rocker member (Fig. 5) and the end walls converge more abruptly in an upward direction from the bottom face of the insulating body to the slot H. Below the ceiling of the transverse slot 55 shoulders 64 are formed where the said slot enters the end walls of the switch chamber, which shoulders serve asstops to limit the swing of the rocker member in both directions (Figs. 2 and 4). If desired, certain portions of the insulating body at 65, 66, and

61 may be removed to reduce the weight of the body. (Fig. 4.)

The insulating body with the various parts carried thereby may be enclosed within any suitable casing or socket either of insulating material or of metal. In the drawing, in Figs. 1

and 2, the insulating body and its attached parts are shown as mounted in a metallic casing or a' socket comprising a shell and a cap made in accordance with United States Letters Patent No. 1,586,367, issued to Frank E. Johnson, on May 25, 1926, in which figure 10 indicates the shell and H a dome-shaped cap. The insulating body is' rugations 16 and locking projections 7'! respec tively in accordance with thedohnson patent.

The upper end of the shell and the flange 15 of the cap are provided with corherei'nbetore referred to for locking the cap on the: shell- When a short socketisrequired for use in limitedspaces in which a socketof standard length cannot be used, a fiat cap may be submitted for the dome-shaped cap. In Figure 8 such a cap 18' is shown provided with a flange "l9 and looking' projections similar to those in the domeshapedi cap which are adapted to lock'with the corrugated end of the shell member. The top of the cap isfiat so that the overall length of the socket is materially shortened. In this con struction', the recess I2 in the top face of the insulating body afiords sufficient room for the knotted lead wires when compressed.

Both' forms of caps may be provided: with a lining 82- and with the usual collar 8| through which the lead wiresmay pass to the terminals and the collar may be provided with an interior'thread for mounting it on the nipple of a fixture and with a set screw 83 for securing it thereon in fixed position.

The process of assembling the various parts of a lamp socket made in'accordance with my invention is very simple and may be rapidly performed because of the elimination of means, such as screws and thelike, for fastening the various parts in the insulating body. The switchparts when mounted in the insulating body are held in operative position by the actuating spring and stalled in electrical construction work, all that is necessary is to remove the cap in the usual way and withdraw the insulating body from the shell a suflicient distance to disclose the binding screws of the two side terminals. the lead wires may then be carried through the collar on. the cap, knotted together, and their ends secured to the binding screws, after which the insulating body is'pushed back into the shell, the cap applied to compress the knot into the recess in the top face of the insulating body and the socket is ready for mounting upon the lighting fixture. When a short socket is required in any lighting fixture, the flat cap shown in Fig. 8 maybe used and the'recess in the top face of the insulating body affords suflicient room for holding the knotted lead wireswhen the cap is mounted and locked to the shell.

In the use of my socket, the'switch is either The ends of opened or closed by pressure exerted upon whichever. push button is in an outermost position which pressure imparts a longitudinal movement to the slide 52 and carries the upper end of the actuating spring over a center and thereby throws the rocker member from one position to the other either opening or closing the circuit as the case may be. operated to close the circuit the rocker member is thrown in between the contacts 42 and ll making a sliding engagement therewith which When the switch is slightly compresses the two resilient arms of r the rocker member together. This action insures a perfect contact. When the rockermember is moved'outwardly from between .thefcontactsiin.

the opening of the circuit, the resiliency of the rocker arms insures engagement with both contacts so long as any engagement is maintained and then disengagement from both. contacts simultaneously which splits the current and reduces arcing to a minimum. a

With this construction of switch, I have found than that herein shown and described all within the scope of the following claims.

What I claim is:

1. In a lamp socket, the combination of an insulating body recessed in its top face to afford space for knotting lead wires and in its bottom face to form a switch chamber, a slotted opening connecting said two recesses, said opening having an interior shoulder at each end adjacent said first recess, a pair of fixed contacts mounted in said switch chamber, a U-shaped rocker member pivotally mounted on said interior shoulders and having arms extending into said switch chamber, said arms being resilient permitting them to move inwardly toward each other when said rockermember is thrown between said fixed contacts, an operating member and an actuating spring intermediate said rocker member and said operating member for rocking said rocker member to turn said resilient arms into or out of sliding engagement between said fixed contacts whenever said'operating member is actuated.

2. In a lamp socket, the combination of an insulating body recessed in its bottom face to form a switch chamber and in its top face to afford a space for knotting the lead wires, said latter recess opening out and down opposite sides of said body to form terminal recesses, a slot'in the floor of said top recess expanding into said switch chamber, said slot 'having at' each end an interior shoulder, a rocker member pivotal- 1y mounted in said slot on'said' shoulders and having resilient arms with reversely turned ends extending into said chamber, a pair of fixedpar allel contacts mounted in said chamber, an actu-.

ating spring mounted at one end on said reversely turned ends and a member connected to the other end of said spring for operating said spring to throw said rocker member into and out of bridging engagement between saidiixed contacts, the floor of said top recess being raised in its central portion to raise the pivotal axis. of said rocker member. I r

3. In a lamp socket, the combination of an insulating body recessed in one face to afford a switch chamber and provided with a slot in its opposite face communicating with said chamber,

said slot having an interior shoulder at each end, a rocker member pivotally mounted on said shoulders and having resilient arm portions extending into said chamber, a pair of fixed con tacts in' said chamber, an operating member and an actuating spring interposed between said operating member and said rocker member for rocking said rocker member into and out'of bridging engagement between said fixed contacts whenever said operating member is actuated,

said spring being under compression at all times to hold said rocker and operating members in operative position in said insulating body with-' out requiring any other supporting or fastening means, the floor of said top recess being raised in its central portion to raise the pivotal axis of said rocker member.

4. In alamp socket, an insulating body recessed in its top face to afford a space for knotting lead chamber, said slot having a shoulder at each end adjacent the floor of said recess adapted to pivotally support a rocker member'extendin'g into said chamber.

, 5. In a lamp socket, the combination of a onepiece insulating body recessed in its top face to afford a space for knotting lead wires, the floor of said recess being elevated in its central portion and said recess opening out opposite sides of said body and extending down said sides to form terminal recesses and having its bottom face recessed to afford a switch chamber, and a relatively narrow slot in the elevated portion of the floor of said top recess, said slot opening into' said switch chamber and being provided with end shoulders adjacent the floor of said recess, said shoulders being adapted for supporting pivotally a bentwire rocker member with'its arms extending'into said switch chamber. 7 A J '6. In a lamp socket, the combination of an in sulating body recessed in its top face to afford a space for knotting lead wires, said recess having a central raised floor portion and opening out opposite sides of said'body and extending down said sides to form terminal recesses and having its bottom face recessed to afford a switch chamber and a slot in the raised portion of the floor of said top recess, said slot expanding into said switch chamber and being provided with end shoulders adjacent the floor of said recess, said shoulders being adapted for supporting pivotally a rocker member with its arms extending into said switch chamber.

'7. In a lamp socket, a one-piece insulating body recessed in its top face to afford space for knot-' ting lead wires and in its bottom face to form a switch chamber, the floor of said recess in its'top face being raised in its central portion and provided with a narrow slot in said raised portion having a shoulder at each end adjacent the top surface of said raised portion adapted to support the head of a rocker member inserted through said slot and having arms extending into' said switch chamber, said slot expanding downwardly into said switch chamber to permit and to limit,

the rocking movement of said member.

'8. In a lamp socket, a rocker member mounted for and adapted to be oscillated into and out of bridging engagement with a pair of fixed contacts to close and to open a circuit therethro-ugh, said rocker member being formed of wire bentinto, a U-shape with its head provided with opposite laterally extending ears adapted to serve'as bearings VI said top recess communicating with said bottom recess, said slot being transversely expanded in a downward direction and having interior end shoulders adjacent said floor, a switch, including a rocker member, mounted in said chamber, said rocker member being mounted in said slot and having ears engaging said shoulders for supporting said member pivotally in said slot, the central portion of said floor being raised in order to raise the axis of pivotal movement of said member.

10. In a lamp socket, the combination of an insulating body recessed in its bottom face to form a switch chamber and in its top face to afiord space for knotting lead wires, a slot in the floor of said top recess communicating with said bottom recess, said slot being transversely expanded in a downward direction and having interior end shoulders adjacent said floor, a rocker member mounted in said slot and having ears engaging said shoulders for supporting said member pivotally in said slot, the central portion of said floor being raised in order to raise the axis of pivotal movement of said member, a pair of fixed contacts in said chamber, an actuating spring and means for operating said actuating spring.

11. In a lamp socket, the combination of an insulating body recessed in its bottom face to form a switch chamber and in its top face to afford space for knotting lead wires, a slot in the floor of said top recess communicating with said bottom recess, said slot being transversely expanded in a downward direction and having interior end shoulders adjacent said floor, a rocker member pivotally mounted in said slot and having arms extending into said chamber and a pair of fixed contacts mounted in said chamber, the space be- 7 tween said contacts being less than the normal width of said rocker member at the arm portions, the arms of said rocker member being resilient permitting them to moveinwardly toward each other when said rocker member is thrown in between said contacts.

12. In a lamp socket, the combination of an insulating body recessed in its bottom face to form a switch chamber, a pair of fixed contacts mounted in said chamber in spaced relation, a slot in the top face of said body having an interior shoulder at each end in close proximity to said top face, a U-shaped bent wire rocker member having its head provided with ears pivotally seated on said interior shoulders and having arm) portions with reversely turned ends extending into said chamber, an actuating spring having one end mounted on said reversely turned ends and a push-button slide connected to the other end of said spring for operating said spring to throw said rocker member into and out of bridging engagement with said fixed contacts, said slot being expanded transversely in a downward direction to limit the rocking movement of said rocker member.

GUSTAF A. JOHNSON. 

